The ligament most commonly used is the patellar ligament which connects the kneecap (patella) to the tibia. About one-third of this ligament is removed and subsequently secured to the femur and tibia to replace the torn ACL. It is estimated that over 90% of patients are able to resume their previous level of activity after ACL reconstruction. A small percentage of patients are bothered by persistent pain or instability; however, changes in activity level following ACL reconstruction surgery are often due to choice rather than limitations of the knee joint.

Lateral Collateral Ligaments
The collateral ligaments act like guy ropes at the sides of the knee, protecting the knee against forces which would tend to pry it open sideways. The collateral ligaments on either side of the knee differ in their anatomy. The LCL is a cord-like structure. The MCL is more of a band, and has both a deep and a superficial component. Of the two, the MCL is the more commonly injured, although the injury is more often a sprain than a complete rupture. MCL injuries can be very painful and are often caused when the knee bends the wrong way when landing, or on high impact. It can take between 2 and 10 weeks for the injury to fully heal. If the collateral is torn, rather than just sprained, an audible 'pop' may be heard. Pain is immediate and experienced over the site of the ligament, the knee may be able to continue to bear weight on that leg, albeit with bent knee. Most collateral ligament injuries will heal themselves with rest and bracing.
There are two menisci in your knee; each rests between the thigh bone (femur) and shin bone (tibia). The menisci are made of tough cartilage and conform to the surfaces of the bones upon which they rest. One meniscus is on the inside of your knee; this is the medial meniscus. The other meniscus rests on the outside of your knee, the lateral meniscus. These function to distribute your body weight across the knee joint. Without the meniscus present, the weight of your body would be unevenly applied to the bones in your legs (the femur and tibia). This uneven weight distribution would cause excessive forces in specific areas of bone leading to early arthritis of knee joint.

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